Smoke can produce a rather toxic-smelling mist with an on-crowd wind but not aware of any staining problems. Did cause a few stains to nether garments after lifting the beer tent with my along-crowd arrival at San Nicole some years ago but that is another story.
A wise man once said to me that you should only display because you enjoy it. If you start to fly for the crowd, turn downwind and land. I managed to display aircraft as diverse as Wessex, Sea Harrier, Yak 50 and Tiger Moth for some 45 years without doing any damage to myself or the crowd (apart from said beer tent). I acknowledge that my reactions may not be quite a sharp as they were in the 70’s, so no longer indulge in low-level aeros.
Still love the flying though!
Mog